Many efforts have been made to provide disposable syringes intended for one-time use. For example: U.S. Pat. No. 3,478,937 to Solowey Nov. 18, 1969, for Disposable Single Unit-dose Syringe with Locking Plunger has pawls 41 pivoted into notches 44 by force of the edge of the rigid collar 46 and after passing through the collar, the pawls spring outward to prevent upward movement of the plunger.
U.S. Pat. No. 3,890,971 to Leeson et al. June 24, 1975 for Safety Syringe describes a detent 19 having an upwardly inclined groove locking face 18b in order to prevent downward movement of the plunger after initial use.
U.S. Pat. No. 4,233,975 to Yerman Nov. 18, 1980 for Anti-drug Abuse Single-use Syringe describes a terminal end blocking flow through outlet 17 when female members 25 flexibly and resiliently snap back into locking position blocking flow into or from needle 22.
U.S. Pat. No. 4,252,118 to Richard et al. for Nonreusable Drug Prefilled Syringe Assembly and Method of Use describes a stopper and rod which become disconnected from each other after an injection is given and the plunger rod is withdrawn inside the barrel.
U.S. patent to Legendre et al. Jan. 11, 1983 for Pre-filled Syringe for Abusable Drugs describes a spike 14 on a plunger rod 13 which prevent the rod from being withdrawn backward through the restricted opening.
U.S. Pat. No. 4,391,272 to Staempfli July 5, 1983, for Disposable Syringe describes a rim 7 of a plunger 6 which is blocked against the body 11 of the groove 5 which prevents the rearward return movement of the piston body 3.
U.S. Pat. No. 4,391,273 to Chiquiar-Arias July 5, 1983, for Non-reusable Disposable Syringes describes a sharp point of pin 67 which penetrates the bottom wall of the cylinder when the plunger is pressed home, making the syringe useless thereafter.
U.S. Pat. No. 4,493,703 to Butterfield Jan. 15, 1985 for Hypodermic Syringe Cartridge with Non-retractable Drive Piston which describes an actuator rod which disengages from an insert 18 when the rod is pulled away from the piston.
U.S. Pat. No. 4,650,468 to Jennings, Jr. Mar. 17, 1987 for Retractable Disposable Syringe describes various locking arrangements in which the cannula is withdrawn into the cylindrical body and securely locked within it.